My rubbish boiler is not up to the job.

[DaydreamJay]

I had a Worcester Bosch Greenstar 28Kw combi boiler fitted last year at the recommendation of a heating engineer. It seemed fine in the summer but now that the weather is cold it isn't up to the task of suplying hot water.

In the summer the hot water it supplied was just about hot to the touch and if running a bath you would not need to put any cold water in. But now that the weather is colder the "hot" water it supplies is not hot enough, it certainly isn't hot enough for a shower as you have to turn the shower tap down to a low flow rate to get any amount of heat from it. If I run a bath the water is only just warm enough and soon goes cold.

Someone told me that the Greenstar is restricted to liftng the water temp by a certain amount and therefore in winter as the input temperatue is lower then so is the output temp. This seems a bit daft as it means that the boiler is virtually useless.

So. Is there a way of modifying the boiler in order to get a bit of performance out of it? In the worst case scenario that I have to replace it, is there a boiler that fits straight on in its place with little modification?

Any advice gratefully received.

Jay

 

[sooey]

Someone told me that the Greenstar is restricted to liftng the water temp by a certain amount and therefore in winter as the input temperatue is lower then so is the output temp. This seems a bit daft as it means that the boiler is virtually useless.

That's the way all combis work, it shouldn't be a problem. From what you say it sounds like your boiler hasn't been set up properly in the first place.
Get the installer back to check it.

 

[WDIK]

is your eco button pressed?
but yes get the installer back thats not been set up correctly

 

[DaydreamJay]

Thanks for the replies. The installer has gone bankrupt unfortunately.

 

[Gasguru]

It should provide about a full bucket of water to bath temperature per minute, ie it takes a long time to run a bath.

 

[ChrisR]

In this weather, more like showering temperature, and it depends on the bucket!

 

[DaydreamJay]

OK so I think it's obvious that this is a low powered boiler. So is it possible to replace it with something more powerful that will fit straight onto the current fittings?

 

[ChrisR]

It isn't a low powered boiler Most people are happy with 28kW, though WB combis go up to 42 kW. Yours might be faulty or starved of gas.
See FAQ on Gas Usage, which I'm about to write, so it'll be near the end.

 

[gas4you]

Although I don't like WB, your boiler is good and should be able to supply all your HW needs, even a bath at this time of year.

Why did the installer go bust? Was it he done a cheap job and didn't fit or set up boilers correctly so he got a bad reputation?

You should be able to get 12 l/min @ 35C temp rise from this boiler.

As others have said you either have a duff installation, poor gas supply or faulty boiler.

If it is still under warranty call WB and book a service call asap.

 

[DaydreamJay]

Although I don't like WB, your boiler is good and should be able to supply all your HW needs, even a bath at this time of year.

Why did the installer go bust? Was it he done a cheap job and didn't fit or set up boilers correctly so he got a bad reputation?

You should be able to get 12 l/min @ 35C temp rise from this boiler.

As others have said you either have a duff installation, poor gas supply or faulty boiler.

If it is still under warranty call WB and book a service call asap.

A 35C temp rise doesn't sound much when the input temperature of the water won't be much more than 5 degrees or so.

 

[Gasguru]

It will fill a standard size bucket in a minute to a normal bath temperature. It is certainly adequate for showering. Measure the flowrate as it appears there is a problem with the boiler (or are you expecting 50 litre/minute showering )

 

[gas4you]

You may get more in reality, especially by slowing the flow through the tap, but if it meets these figures then WB will say it is working ok.

Realistically I would expect a bit more.

Very rare to get incoming water at less than approx 10C.